scholarly journals thermodynamic quality of solvent in polymer chemistry

2008 ◽  
Keyword(s):  
Polymer Chemistry ◽  
Thermodynamic Quality

scholarly journals Study of the formation of structures in solutions of chitosan – polyvinyl alcohol polymer blends

2021 ◽  
Vol 23 (2) ◽  
pp. 188-195
Author(s):  
Rinat M. Akhmetkhanov ◽  
Valentina V. Chernova ◽  
Angela S. Shurshina ◽  
Mariya Yu. Lazdina ◽  
Elena I. Kulish
Keyword(s):  
Polyvinyl Alcohol ◽  
Polymer Blends ◽  
Intrinsic Viscosity ◽  
Solvent Interaction ◽  
Polymer Aggregates ◽  
Macromolecular Coil ◽  
Aggregation Processes ◽  
Huggins Constant ◽  
Thermodynamic Quality

The aim of this work was the investigation of the formation of structures in solutions of individual polymers, as well as their blends with each other in buffer solvents with different values of pH. In this study we used a sample of chitosan (degree of deacetylation ~ 84 %, M = 130,000), which is a polycation when dissolved, and polyvinyl alcohol (r = 1.25 g/cm3, M = 5000). Buffer systems based on acetic acid and sodium acetate with pH = 3.8, 4.25, and 4.75 were used as solvents. Viscosimetry was used to determine the intrinsic viscosity, the degree of structuring, and the Huggins constant. The Kriegbaum method was used to determine the nature of the aggregates formed by the blend of the studied polymers. In the course of the research, it was shown that an increase in the pH of the acetate buffer used as a solvent was accompanied by a compression of the macromolecular coil (a decrease in intrinsic viscosity values), a deterioration in the quality of thesolvent (an increase in Huggins constant values), and an increase in the degree of polymer aggregation in a solution for chitosan polyelectrolyte. At the same time for a solution of polyvinyl alcohol the pH of the buffer practically did not affect the nature of the polymer-solvent interaction. It has been proved that polymer blends are characterized by an increase in aggregation processes and a decrease in the thermodynamic quality of the solvent in comparison with solutions of individual polymers. The size of the “combined” macromolecular coil, characterized by the intrinsic viscosity value for the polymer blend, which can be both above (buffer solvent with pH = 3.80) and below (buffer solvent with pH = 4.25 and 4.75) additivevalues, changed depending on the type of formed polymer-polymer aggregates (homo- or hetero-). It was established that the type of aggregates (homo- or hetero-) formed in solutions of polymer blends was determined not only by the thermodynamic quality of the used solvents, but also by the concentration of the polymers in the initial solutions

Kinetic manifestation of the thermodynamic quality of a medium in three-dimensional polimerization of oligoether acrylates

1989 ◽  
Vol 31 (6) ◽  
pp. 1351-1355
Author(s):  
D.K. Vasilev ◽  
I.M. Belgovskii ◽  
I.V. Golikov ◽  
M.M. Mogilevich
Keyword(s):  
Three Dimensional ◽  
Thermodynamic Quality

Effect of temperature and thermodynamic quality of solvent over unperturbed chain dimensions of nylon 6

2011 ◽  
Vol 122 (4) ◽  
pp. 2351-2358 ◽  
Author(s):  
Musa Kaleem Baloch ◽  
Mohsan Nawaz ◽  
Arjamand Bano
Keyword(s):  
Nylon 6 ◽  
Effect Of Temperature ◽  
Thermodynamic Quality

Effect of the thermodynamic quality of the solvent on chain termination in radical polymerization

1989 ◽  
Vol 31 (10) ◽  
pp. 2364-2368
Author(s):  
L.A. Smirnova ◽  
Yu.D. Semchikov ◽  
T.G. Sveshnikova ◽  
D.N. Yemel'yanov ◽  
N.A. Ignat'yeva ◽  
...  
Keyword(s):  
Radical Polymerization ◽  
Chain Termination ◽  
Thermodynamic Quality
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